Process and apparatus for the manufacture of moldings and shaped sections from fiberboards, wood pulp boards, crushed cane boards, beaver boards, and the like



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NUFACTURE OF MOLDINGS AND 2 Sheets-Sheet l J. R0 ERS US FOR THE MA Nov. 6, 1934.

PROCESS AND APPARAT SHAPED SECTIONS FROM FIBER BOARDS, WOOD PULP BOARDS, CRUSHED CANE BOARDS.' BEAVER BOARDS, AND THE LIKE A Filed May 4, 1935' J. ROGERSON Nov. 6, 1934.

1,979,905 PROCESS ANDAPPARATUS FOR THE MANUFACTURE OF MOLDINGS AND SHAPED SECTIONS FROM FIBER BOARDS, WOOD PULP BOARDS, CRUSHED CANE BOARDS. BEAVER BOARDS, AND THE LIKE Filed May 4, 1935 2 Sheets-Sheet 2 J R i jil yewrgg mm BM Patented Nov. 6, 1934 UNITED STATES PATENT OFFICE PROCESS AND APPARATUS FOR THE MANU- FACTURE OF MOLDINGS AND SHAPED SECTIONS FROM FIBER BOARDS, WOOD PULP BOARDS, CRUSHED CANE BOARDS, BEAVER BOARDS, AND THE LIKE Application May 4, 1933, Serial No. 669,428 In the Union of South Africa July 2, 1932 2 Claims. -(Cl. 51--206) This invention relates to a process and apparatus for the formation of moldings and shaped sections from fiber boards, wood pulp boards, crushed cane boards; beaver boards and similar materials, all of which are for convenience hereinafter referred to as fiber boards.

The process and apparatus can also be used for the cleaning up of moldings and shaped sections made of wood.

Fiber boards are now extensively used for many purposes in the construction of buildings, for example, for walls and ceilings, for sound deadening purposes and many other purposes and more recently they have become increasingly used for decorative purposes.

The extensive use to which fiber boards are now put necessitates some process being available for fashioning moldings and shaped sections. The difficulty in the construction of these moldings and shaped sections hitherto experienced is on account of the fact that it is not easy to work the materials owing to their fibrous nature and the wheels of steel cutters normally produce rough edges and an unfinished appearance.

My invention consists in the fashioning of the molding and sections by the use of a high speedwheel with an abrasive rim.

I deal below with the particular type of abrasive that I find most suitable in practice and the particular method which I have also found most suitable for the fixing of such abrasive but I do not limit myself to such abrasive or method of fixing.

Similarly I deal below with the shape of cutting wheel and method of construction; here again I do not limit myself to such shape or method.

In general it has been found by me in practice that if a cutting wheel is used with abrasive extending right round the circumference of the rim there is a definite tendency to burn the molding at high speeds. For this reason, as will be made clear below, the abrasive coated wheel (or head as I shall for convenience hereinafter term the wheel) is provided at intervals round the circumference with gullets which prevent the burning of the moldings and ensure a cleaner cut, the number of gullets varying in accordance with the density and texture of different brands of fiber board.

In general the heads are of two slightly different forms, in the first the abrasive extends continuously round the rim between the various gullets spaced round the rim; in the second the abrasive is formed into a series of ridges around the rim between the gullets, thus forming a series of cutting edges. The details of these two main types will now be described and for this purpose I refer to the annexed drawings, in which drawings:

Figure 1 is a side elevation of a head of the first type.

Figure 2 is a section of a head of the first type on the line A-A in Figure l.

Figure 3 is a diagrammatic view of a portion of a head of the first type showing by way of example a portion of the rim with abrasive applied and another portion of the rim before the abrasive has been applied, the latter portion of the rim showing the indentations or serrations.

Figure 4 is a similar view to Figure 3 but in which the rim of the head instead of being indented or serrated is grooved with a series of grooves to ensure an even greater degree of binding between the abrasive mixture and the rim of the head.

Figure 5 is a cross-sectional view of a molding constructed by means of the head illustrated in Figures 1, 2, 3 and 4.

Figure 6 is a diagrammatic view of a head of the second type in which a sector is shown with the abrasive in position forming four abrasive ridges whilst in the remaining seven sectors the rim of the head is shown as shaped before the abrasive has been applied.

Figure '7 is a sectional view on the line BB in Figure 6, the figure showing how a composite head is made up for the purpose of the more elabcrate types of moldings.

Figure 8 is a cross-section of a molding fashioned by means of the head illustrated in Figure 7.

Figure 9 is an isometric view of a similar type of head to that illustrated in Figures 6 and '7.

In Figures 1,, 2,. 3, 4 and 5 above the main body (1) of the head is provided with gullets (2) spaced round the rim of the head. In the drawings four gullets are shown to the head but if desired a larger or smaller number may be employed according to, the type of material being worked and the grade of work desired. Indentations or serrations (3) are made in the rim of the head as shown in Figure 3, or alternatively grooves '(4) as shown in Figure 4 may be employed, these indentations or grooves, as the case may be, ensuring when the abrasive is applied in the manner hereinafter described it will rigidly adhere to the surface of the rim, thus minimizing the risk of the cutting surface breaking away from the he d in operation. The abrasive mixture (5) is In Figures 6, '7, 8 and 9 the main body (10) of the head is provided with gullets (11) spaced around the rim of the head. In the drawings eight gullets are shown in Figure 6 and in Figure 9, but if desired a larger or smaller number may be employed according to thetype of material being worked and the grade of work desired. The head is turned to a diameter somewhat less than the diameter of the head as ultimately required and a series of slots (12) is cut in the rim of the head leaving in position in the form of a cog Wheel teeth the rim projections (12a). The

abrasive mixture is applied to the rim of thewheel by being inserted in the slots (12) thus forming the abrasive ridges (13) each ridge of abrasive mixture so formed projecting slightly beyond the actual circumference of the head itself, thus providing a series of cutting edges (14) A central hole (15) is again'provided by means of which the head may be mounted on a spindle.

In Figures '7 and 9 showing the constructiton of a composite type of headthere are three separate heads (10), (10a) and (101)), all mounted on a common spindle and having plates (16ibetween adjoining heads for the purpose of spacing the heads at the required distances apart to perform any particular desired shape of moldingi In the construction of heads fashioned in accordance with the-illustrations above described, the head is constructed preferably of wood and may be either in one piece of if greater strength is desired may be of ply wood. The head is turned in such a fashion as to ensure the contour of the rim having a shape exactly the reverse of the contour subsequently to begiven to the molding. In practice I have found that the diameter of the head may suitably be of from five to, eight inches,

but I do not limit myself to these dimensions.

The heads are. turned so as to have a diameter slightly smaller than the diameter ultimately required and thereafter the gullets are bored round the circumference. Where a head as illustrated in Figure 3 is being constructed the surface of the rim is at this stage serrated or indented to a depth of about one sixteenth of an inch to ensure the abrasive mixture when applied penetrating into the fibers of the wood and so preventing the cutting surface breaking away when the head is in operation. Similarly in the case of a head constructed according to Figure 4:, the grooves are at this stage cut in the surface of the rim. Thereafter in the case of heads constructed according to both Figures 3 and 4, cores. are inserted in the gullets so as to prevent the abrasive mixture escaping into and blocking up such gullets. The cores are so fashioned, however, so as to allow the abrasive mixture to project very slightly into the gullet spaces, i. e. beyond the walls of the gullet. The purpose of this is to provide a keen cutting edge projecting into the gullet spaces.

"Templates are temporarily fastened on either Side of the head, the circumference of the templates being the exact diameter ultimately required and an abrasive mixture is then applied by being spread evenly over the rim between the templates, any excess mixture being smoothed off with a straight edge so bringing the abrasive mixture on the rim up to the exact level of the templates around the Whole circumference.

The same procedure is adopted in the construction of heads fashioned according to Figures 6, 7 and 9, save that cores are also provided around the rim of the head so as to prevent the abrasive mixture running over from the spaces (12) on to the rim projections (1211). When such cores and the cores in the gullets are removed the abrasive ridges (13) project around the circumference of the head and form the means by which grooves and shapes are actually out into the moldings.

Any suitable method of applying the abrasive mixture to-th'e heads may be employed; for example, a mixture containing carborundum grit No. 33 or other suitable abrasive may be used which has the quality of being plastic for a sufficient length of time to enable the mixture to be applied to the head but which thereafter hardens to a sufficient degree of hardness for the purpose of cutting fiber boards. Such hardening may be effected by any suitable method at present employed for hardening abrasive mixtures.

-In operation the head or heads are mounted to a shaft to which they are securely keyed or bolted. The shaft is run at a high speed; I find in practice a speed of about 4000 to 5000 revolutions per minute suitable.

The fiber boards to be worked are "fed towards the cutting wheel upon a table arranged below the cutting head resulting in moldings of the shape desired being cut or ground in the fiber board.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed I declare that what I claim is:

1. An apparatus for the manufacture of moldings and shaped sections of fibrous articles com prising a wheel provided with two sets of peripheral recesses, one set being relatively shallow, abrasive blocks anchored in the shallow recesses and projecting beyond the periphery of the wheel to provide spaces therebetween, the other set of recesses being of greater depth and dividing the shallow recesses into groups, the second mentioned recesses and the spaces between the blocks forming channels for the passage of a cooling medium.

2. An apparatus as claimed in claim 1 wherein the second mentioned set of recesses of greater depth are also of greater width in the direction of the circumference of the wheel than the first mentioned recesses.

JOSEPH ROGERSON. 

